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Biomedical subjects

T Tamura

Publications and source records attributed to T Tamura.

At least 1,045 records · Page 58Linked to original sources
PubMed1988

Ampicillin concentrations in human dental granuloma after a single oral administration of talampicillin.

Ampicillin concentrations in human serum and dental granulomas of 31 patients were determined after a single oral dose of talampicillin (equivalent to 500 mg of ampicillin) was administered to each. The specimens were taken at 1.5, 2.0, 2.5, 3.0, and 3.5 h after the administration of talampicillin. The mean peak ampicillin concentrations in serum and dental granulomas occurred at identical times, 2.5 h, and were 8.29 micrograms/ml (range, 1.81 to 13.20 micrograms/ml) and 2.94 micrograms/g (range, 1.14 to 7.16 micrograms/g), respectively. The mean dental granuloma/serum ampicillin concentration ratio at the peak time (2.5 h) was 0.42 (range, 0.29 to 0.56). Ampicillin concentrations in dental granulomas exceeded most of the MICs for the bacteria commonly isolated from odontogenic infection.

Administration, Oral↗
PubMed1988

Isolation of a transformation-defective mutant of the McDonough strain of feline sarcoma virus exhibiting tyrosine kinase activity in vitro but not in vivo.

NRK cells transformed by the McDonough strain of feline sarcoma virus (SM-FeSV) were mutagenized by the use of 5'-azacytidine. Four cell lines expressing different transformation-defective phenotypes were isolated. Superinfection of these cell lines with simian sarcoma-associated virus (SSAV) led in three instances to the recovery of transforming virus particles carrying an intact fms gene. A nonconditional transformation-defective virus, designated td26-SM-FeSV (SSAV), was isolated from one of the cell lines. NRK cells infected with this mutant contained actin cables and fibronectin networks and exhibited normal cell morphology. Such cells formed only small colonies in soft agar and exhibited a mitogenic activity similar to that of noninfected cells. Cells infected with td26-SM-FeSV (SSAV) synthesized a gag-fms fusion glycoprotein (gp180gag-fms). This polypeptide was processed in the normal manner into the intracellular gp120v-fms and a transformation-defective gp140td-v-fms which was expressed at the surface of infected cells. This species had an increased electrophoretic mobility on polyacrylamide gels compared with the molecule from wild-type virus.gp140td-v-fms had endo-beta-N-acetylglucosaminidase H-resistant carbohydrate side chains. No tyrosine kinase activity was detectable in vivo in td26-SM-FeSV (SSAV)-infected cells even when the cells were treated with sodium orthovanadate. In vitro, fms molecules from td26-SM-FeSV (SSAV)-infected cells exhibited tyrosine kinase activity as determined by autophosphorylation and phosphorylation of exogenous (poly)Glu-Tyr. At low ATP concentrations (less than 5 microM) this in vitro tyrosine kinase activity was significantly reduced compared with that of the wild-type counterpart.

Antigens, Surface↗
PubMed1988

Passive properties of canine left ventricle: diastolic stiffness and restoring forces.

Left ventricular (LV) diastolic pressure-volume (P-V) relations arise from a complex interplay of active decay of force (i.e., relaxation), passive elastic myocardial properties, and time-varying inflow across the mitral orifice. This study was designed to quantify the passive properties of the intact ventricle and the effects of elastic recoil by separating filling from relaxation with a method of LV volume clamping with a remote-controlled mitral valve. Eleven open-chest fentanyl-anesthetized dogs were instrumented with aortic and mitral flow probes, LV and left atrium micromanometers, and a remote-controlled mitral valve. We prevented complete (end-systolic volume clamping) or partial filling at different times in diastole. The ventricle thus relaxed completely at different volumes, and we generated P-V coordinates for the passive ventricle that included negative, as well as positive, values of pressure. We then estimated ventricular volumes from ventricular weight in eight dogs, using regression equations based on data in the literature, to determine the equilibrium volume (V0), that is, volume at zero transmural pressure, in the working ventricle. We abandoned the traditional exponential approach and characterized by the P-V relation with a logarithmic approach that included maximum LV volume (Vm), minimum volume (Vd), and stiffness parameters (Sp and Sn) for the positive (p) and negative (n) phases: Pp = -Sp In[(Vm - V)/(Vm - V0)] and Pn = Sn In[(V - Vd)/(V0 - Vd)]. With this formulation, the chamber compliance, dP/dV, is normalized by the LV operating volume, and Sp and Sn are size-independent chamber stiffness parameters with the units of stress. In eight ventricles with LV weight = 131 +/- 20 g, Vm = 116 +/- 18 ml, V0 = 37 +/- 6 ml, and Vd = 13 +/- 2 ml, stiffness Sp = 14.6 mm Hg and Sn = 5.1 mm Hg were determined from the slopes of the log-linearized equations. Also, the duration of LV relaxation is increased by the process of ventricular filling (161 +/- 31 msec, filling versus 108 +/- 36 msec, nonfilling, measured from dP/dtmin, p less than 0.0001). We conclude that volume clamping is a useful method of studying restoring forces and that the logarithmic approach is conceptually and quantitatively useful in characterizing the passive properties of the intact ventricle.

Animals↗
PubMed1988

Time-course study of gastric damages in rats by anti-inflammatory drugs using a gastroscope and its quantification.

Time-course studies on gastric damages in rats caused by nonsteroidal anti-inflammatory drugs (NSAIDs) were performed using a gastroscope, and the readings were quantified to obtain the Congestion-Hemorrhage Index (CHI) for evaluating the potencies of the damaging properties of NSAID. The correlation between CHI and Ulcer Index (UI), the quantified value obtained by the conventional methods, was highly significant at 6 and 24 hr after forced oral administration of NSAID. The peak CHIs of aspirin (300 mg/kg), indomethacin (60 mg/kg), mefenamic acid (300 mg/kg) and fenoprofen calcium (300 mg/kg) appeared approximately 24 hr after a single forced oral administration of drugs. Thus, it was suggested that an observation at 24 hr in addition to one at 6 to 7 hr might be necessary for the examination of damaged gastric mucosa. Under the present experimental conditions, fenoprofen calcium caused the greatest damages on gastric mucosa among the four NSAIDs. Mefenamic acid showed the least damaging potency on gastric mucosa, having a smaller CHI than that of aspirin. Indomethacin possessed a stronger damaging property than aspirin.

Animals↗
PubMed1988

Prolactin release in polycystic ovarian syndrome.

To evaluate the prevalence of hyperprolactinemia in patients with polycystic ovarian syndrome (PCO), 72 patients with oligo- or anovulation were studied. All of the patients had persisting elevated LH (greater than 25 mIU/ml), normal FSH, high LH/FSH ratio (greater than 2.5), and exaggerated LH responses to LHRH. Mean testosterone and androstenedione concentrations were appreciably increased in these patients. Out of 171 samples for prolactin (PRL) determination from these 72 patients, only 5 patients had a PRL value above 30 ng/ml during the first sampling. The next sampling from these same 5 women disclosed that they were transiently hyperprolactinemic because the next samples showed a normal PRL value. To further investigate the PRL secretory capacity 500 micrograms of TRH and 10 mg of metoclopramide (MCP) were administered to these 72 and 44 patients, respectively. The PRL response to MCP was significantly blunted in these patients compared to normal women while the PRL response to TRH in these patients was not indistinguishable from that in normal women. These results indicate that the true prevalence rate of hyperprolactinemia in PCO may be low rather than high and the association of hyperprolactinemia with PCO may be coincidental rather than a pathogenically related phenomenon.

Adolescent↗
PubMed1988

Histological study of the hydroxyapatite-collagen complex implants in periodontal osseous defects in dogs.

This study was performed to determine whether the process of wound healing, following periodontal surgery, could be improved through the combined use of collagen and grafting of hydroxyapatite (HAP) particles. Twenty-four proximal defects were made in the mandibular fourth premolars and second molars of six adult mongrel dogs. Steel wires and resin were put into the defect to enhance plaque formation. At eight weeks, the wires and resin were removed. At ten weeks, HAP or HAP-collagen complex was implanted during reconstructive surgery, along the root surface treated with acid conditioning. Dogs that received no implant following a flap operation served as controls. In these three groups of animals, differences in the extent and features of healing were histopathologically examined two months later. Animals implanted with a HAP-collagen complex showed a larger amount of new cementum formation when compared with HAP-implanted or control animals. In addition, in animals from the HAP-complex group, the interdigitation between the root surface and the gingival connective tissue fibers tended to be reinforced resulting in suppressed epithelial downgrowth. However, neither bone formation nor the reformation of the periodontium was promoted in the HAP-collagen complex group. These results suggest that implantation of an HAP-collagen complex promotes cemento-genesis of the demineralized root surface and can establish a stronger interdigitation between the root surface and the gingival connective tissue fibers.

Alveolar Process↗
PubMed1988

Effects of gonadotrophins, steroid hormones, and epidermal growth factor on the in vitro proliferation of chicken granulosa cells.

Effects of gonadotrophins, steroid hormones, and epidermal growth factor (EGF) on the in vitro proliferation of granulosa cells obtained from the second largest follicles of laying hens were examined. It was observed that follicle-stimulating hormone and luteinizing hormone as well as EGF significantly promoted proliferation of these cells, unlike estradiol and progesterone. These results suggest that gonadotrophins as well as certain growth factors may be involved in proliferation of chicken granulosa cells.

Animals↗
PubMed1988

[Phase II study of a three-drug combination of ifosfamide, cisplatin and vindesine in non-small-cell lung cancer].

Between February 1986 and April 1987, we conducted a phase II clinical trial of a three-drug combination of ifosfamide, cisplatin, and vindesine in advanced non-small-cell lung cancer. The combination consisted of ifosfamide, 1,300 mg/m2, on days 1 through 5, cisplatin, 20 mg/m2, on days 1 through 5, and vindesine, 3 mg/m2, on days 1 and 8. Courses were repeated at 4-week intervals until disease progression or unacceptable toxicity occurred. Of 21 patients evaluated, one had a complete response and 12 had partial response, with an overall response rate of 62%. The projected median response duration was 30 weeks. The median survival for all patients has not been reached: 14 of 21 patients are still alive with a median follow-up period of 41 weeks (range, 12 to 73 weeks). The major toxicity was myelosuppression. One patient died of septicemia while neutropenic, but the toxicity was well tolerated in the rest. These results indicate that this three-drug combination is active against non-small-cell lung cancer and warrants further clinical trials.

Adenocarcinoma↗
PubMed1988

Treatment for small cell lung cancer--present status and future prospects.

Strategies for the treatment of small cell lung cancer (SCLC) were reviewed depending on the recent results of treatment. The development of new anti-cancer drugs are essential for the further improvement results of SCLC. However, the candidate of patient for phase II study of new anticancer drug is controversial. Intensified chemotherapy is essential in order to obtain long term survivors, however, the toxic death rate should be less than 5% of whole patients. The theory of non-cross resistant alternative chemotherapy has also been applied to the treatment of SCLC. The protocol study supported by grant-in-aid from the Ministry of Health and Welfare is now on-going by cooperative study. There are many discussions about the efficacy of combined modality in SCLC. However, present randomized trials gave clear answers about the priority of combined modality in SCLC. There are numerous biological studies about SCLC. These studies will contribute to improve the treatment results of SCLC.

Carcinoma, Small Cell↗
PubMed1988

Antiinflammatory and antiallergic effects of a novel metabolite of Nocardiopsis sp. as a potent protein kinase C inhibitor from microbial origin.

The antiallergic and antiinflammatory effects of the new protein kinase C and calmodulin inhibitor K-252a (8R, 9S, 11S)-(-)-9-hydroxy-9-methoxycarbonyl-8-methyl-2,3,9,10-tetrahydro-8,11- epoxy-1H,8H,11H-2,7b,11a-triazadibenzo [a,g]cycl oocta [cde] trinden-1-one) were investigated in animal models, and the following results were obtained: 1. Oral administration of K-252a, ketotifen or oxatomide showed a dose-dependent inhibition on 48 h homologous passive cutaneous anaphylaxis in rats and anaphylactic bronchoconstriction in passively sensitized guinea pigs. 2. K-252a (1-100 mg/kg p.o.) exerted a dose-dependent protection against platelet-activating factor (PAF)-induced mortality in mice. This protective effect of K-252a was sustained for 7 h. 3. K-252a (1-100 mg/kg p.o.), as well as dexamethasone (1 mg/kg s.c.), showed remarkable inhibitory effects on rat paw edema induced by carrageenin, zymosan, PAF, and antigen-antibody reaction (passive Arthus reaction) and on the croton oil-induced rat ear edema. On the other hand, indomethacin (10 mg/kg p.o.) significantly inhibited carrageenin-induced edema, but did not inhibit edema induced by other phlogistic agents. Based on these results it is suggested that K-252a, by oral administration, has antiallergic and antiinflammatory effects.

Anaphylaxis↗
PubMed1988

Beneficial effect of prostaglandin E1 in three cases of lupus nephritis with nephrotic syndrome.

Prostaglandin E1 was intravenously injected daily for 4 weeks to three patients with lupus nephritis accompanied by severe nephrotic syndrome. Histologic examination revealed diffuse proliferative or membranous glomerulonephritis. Proteinuria decreased markedly 1 year after the treatment with improvement in hypoproteinemia in all three patients. Five years later, the conditions of three cases ameliorated further.

Adult↗